Greetings folks, hoping someone can shed some light on a heating problem. The above named furnace has been working flawlessly for 16+ years ( other than a thermocouple replacement), natural gas forced hot water with 4 zones. We recently added a 5th zone ( basement ) and the additional zone works occasionally at best. Replaced the thermostat, also swapped TACO valves between zones but the problem remains. Symptoms are, thermostat is turned on, furnace kicks on but burner never fires. Once or twice when the burner did fire, no heat was sent to the zone and the furnace shut down a minute or two later.
Could it be the valve is not opening? I'm stumped at this point, all other zones working fine.

Thanks in advance for any/all info.

BuddyD

 

Hello and welcome....

Well does it work or doesnt it is the question... Your comments kind of contradict...

Does the loop ever get warm or never?

If the zone valve was not opening the boiler would not fire for that zone...

Possibly its opening and the zone is air bound???

What does the pressure and temp gauge read on the boiler...

Can you take pics of the boiler and all around piping? Always helps as we see things sometimes the homeowners don't...

 

Thank you for the quick reply, lawrosa. Today, no it's not working. IF the boiler fires, which it has once today, the loop does not get hot/warm. NONE of the zones do. I've had all other zones off when this particular zone fired and no heat on any pipes at the furnace. The gauges read ~50lbs psi and 150 Fahrenheit.
Good point re: air bound, I'll check that.

I'll take some pics after checking the above.

Again, thanks for the suggestions. More to follow.

 

Can you double check that? You may be reading from the wrong line on the gauge... Should not be over 30psi...

No zones in the whole house???

Possibly your circulator is not functioning...

 

My bad, right @ 30 psi and 220 F ( it's a tough spot to get in to and get a good look ). All 4 original zones working perfectly, only the new 5th zone not functioning. I've also checked for air (opened the spigot ), still not working. I put the thermostat on, wait and it seems to start the "first" stage but the burner never fires. It will remain in that first stage until I shut the thermostat off.

 

Did it ever work bud?????

I would say..

1. air in the line and you are not purging correctly
2. mis wiring for that zone, or faulty zone valve

Very important... The PSI and temp are way too high... You need to lower the temp at the aquastst and service your expansion tank most likely...

Possibly your gauge is not giving a correct reading too and may need to be replaced...

As I said pics will help

 

Thanks.

Yes, work was completed in the summer and it appeared to work. It is now VERY intermittent. Seemed to work for a few weeks but now...had it working one night last week but...next day no luck.

Hmmmm...I drained a bucket or more from the line, seemed to be a steady stream but...

Not sure how to lower the temp. If I remember correctly, the expansion tank should be @ 14lbs?? I verified that, air purger was replaced as part of the zone expansion.

Sounds like I may need to get a "professional" to check things out. Maybe it's time after 16 years, huh?!

Thanks for the advice, much appreciated. I'll post pics as soon as I can.

 

Working on the pictures, some additional info. While draining the line, I noticed the water seems very murky/rusty. Not sure if that means anything or not, especially where the new zone has that new flexible tubing ? ( Can you tell I'm a clueless homeowner )

As far as the wiring goes, all 5 zones are daisy-chained together. I'm assuming this is industry standard?

And...what is the easiest way to post the pix?

Thanks again, lawrosa!

 

What kind of zone valves do you have and what powers them.

 

The best way to post pics is to post them on a photo sharing website such as photobucket.com & provide a link here to the album.

Spott brings up a good point. If there are too many zone valves on one transformer it won't have enough capacity to power all of them. Obivously the last one in line (presumably the new one) will suffer the most.

 

Taco's...electric.

Thanks for asking

 

Taco makes a couple of zone valves for residential heating. The transformer requirements are vastly different. Please tell me which of these two styles you have.

Taco-Hvac: Zone Sentry® Zone Valve

OR

Taco-Hvac: 570 Gold Series

 

Assuming you have the Taco 570 you need at least two 24v transformers. Some people would use three but at least two. Simply put terminals 1 & 2 on the zone valve react to the t-stat, and terminals 2 & 3 go to TT on the aquastat to turn on the burner.

I know you said yours re daisy chained which I personally don't care for and it is not the industry standard.
Either way, at the end of the day the t-stat makes 1 & 2 which makes an end switch in the ZV, and activates 2 & 3 which activates TT in the aquastat & turns on the burner. No. 2 terminal is a common terminal to 1 & 3.

 

Thanks for the ongoing advice. The tacos say 571-2 on the side of them, I'll include in the pix. It also looks like a second 24v transformer was added as part of the recent zone addition, I'll see if I can get the electrician and find out for sure. I'll also include that configuration in the pix.

One other correction, the furnace appears to be running @ 20 PSI, not 30 as I stated yesterday.

And...one of the contractors guys showed up last night to assess the situation, the burner fired right up when he was here. Just tested it again and it fired but it ALWAYS shuts down well short of the set temperature, usually runs for 2 -3 minutes and then shuts down. Temperature comes up maybe a degree.

The new valve/zone was placed next to last in the chain. The last zone is my main floor and has been fine. We'd know based upon the winter we've had

Pictures will follow.

Thanks again.

BuddyD

 

https://plus.google.com/photos/10233...185?banner=pwa

 

Please post the pix on a site such as Photobucket which doesn't require a sign-up/password.

The pressure is fine. Just because the burners shut down, does not mean there is not hot water circulating. After the burners shut down, check the temp on the boiler then wait a 5 or 10 minutes & check it again.

Some thermostats don't like Taco heat motor zone valves & will cause an early shut down. The round Honeywells are particularly bad. Some require the addition of a resistor.

 

Buddy,
I'm sorry but I can't see the pics. By the numbers I know what you have though.
Where as you already had 4 zones you should have had 2 transformers already.
Taco zone valves need a .9 amps. to operate correctly, which is high compared to other ZV's.
They are not compatible with some T-stats.

What do you have for a t-stat and what are the old ones that work.

As Grady said, just because your boiler shuts off it doesn't mean your pump stopped.
The boiler might have reached limit, especially if only 1 zone is calling.

 

I will repost. Most of the t-stats are Honeywells, one Lux. I replaced most of the original Honeywells with programmables, one original remains and it seems to work fine. The new (5th) zone thermostat was a round Honeywell, I replaced with a "cheap" digital Honeywell. Interesting info about the t-stats, though, thank you.

Any recommendations for t-stats that work well with the ZV's I have?

Appreciate the continued support.

Buddy

 

What are the model numbers of the thermostats. We can look up the manuals for them to see if there is anything there about heat motor zone valves.

 

Hi folks,

Apologies for the delay in response/update. I am happy to report that the problem seems to be solved, though I'm not quite sure what exactly solved it.
Thanks to some advice here, I made two changes: 1) swapped out/exchanged the electrical component of the taco valves between 2 zones. Both zones appear to be working fine and 2) bleeding the zone, I go some air but not enough to cause a problem I thought...

Again, thanks to some great advice here I am now looking at all of the t-stats and plan to have a thorough inspection/tune-up prior to next years heating season.

Thanks to EVERYONE who responded and offered advice, suggestions, etc. your help was greatly appreciated. Who knows how much $$ you folks saved me. I hope some day I can return the favor!

 

You are more than welcome. We are glad to have been able to help in one way or another.

Regarding returning the favor: Everybody is knowledgeable about something & I'm sure you are no exception. Feel free to browse our dozens of forums. You have the answer to someone's question about something. Thanks for coming & allowing us to help with your heating problem.